JP2022553937A - Vacuum region regulator with pressure measurement function - Google Patents

Abstract

A vacuum regulator (10) for an active element movable in a process atmosphere region, comprising a coupling (18) and an electric motor (12), cooperating with the coupling (18) to a drive unit that makes the coupling (18) adjustable from a normal position to an active position and back. The apparatus comprises a mechanical interface for connecting the vacuum control device (10) to the process space providing the process atmosphere and a dynamic isolation device (15) for isolating the process atmosphere from the external atmosphere area (A). ) and a control processing unit at least electrically connected to the drive unit and designed to control the electric motor (12). The control processing unit is designed to derive motor state information based on the magnitude of the motor operating parameter and to derive a load differential by comparison of the motor state information to a known motor target state, and Based on the difference, it has a pressure measuring function designed to derive the differential pressure between the external atmosphere area (A) and the process atmosphere area (P).

Description

The present invention relates to a vacuum regulation device for moving and positioning an active element connectable to a drive unit by a coupling within a process atmosphere.

Such adjustment devices designed for vacuum applications are used, for example, to position substrates to be processed in vacuum chambers. Substrates are typically introduced into the process space by a robot where they must be placed at predetermined mounting points within the chamber and lifted off from these points after processing. This positioning and movement within the process chamber is achieved by special adjustment devices, so-called pin lift systems, also called pin lifters.

Pin lifting systems are particularly used in vacuum chamber systems in the manufacture of ICs, semiconductors, flat panels or substrates, which must be performed in a protected atmosphere that is as free of contaminating particles as possible.

Such vacuum chamber systems are in particular provided for housing semiconductor devices or substrates to be processed or manufactured, and are capable of guiding the semiconductor devices or other substrates into and/or out of the vacuum chamber, at least It includes at least one vacuum chamber having one or two vacuum chamber openings. For example, in a semiconductor wafer or liquid crystal substrate manufacturing line, very delicate semiconductor or liquid crystal elements are sequentially passed through several process vacuum chambers, each processed by one processing apparatus.

Such process chambers often have additional adjustment devices, such as transfer valves, the cross-section of which is adapted to the substrate and the robot, through which the substrate can be introduced into the vacuum chamber and where necessary. can be removed after its intended treatment. Alternatively, a further control device (transfer valve) may be provided for removing the processed substrate from the chamber.

Substrates, e.g. wafers, are e.g. guided by an appropriately designed and controlled robotic arm, which can be moved through an opening in the process chamber provided by a transfer valve. After the substrate is lifted or gripped by the robot arm, the substrate is loaded into the process chamber, and the substrate is placed in a predetermined manner, the process chamber is put into operation. The process chamber can be evacuated in a corresponding manner.

Relatively high precision and mobility of the substrate must be ensured for placement and accurate positioning of the substrate within the chamber. To this end, the pin lifting system used can provide multiple support points for supporting the substrate, thereby providing load distribution (due to the substrate's own weight) across the substrate.

The substrate is placed by the robot on the extended lifting pins of the lifting system and by lowering the pins it is placed on a carrier, eg a potential plate (chuck). For this purpose, the robot arm carrying the substrate is usually moved out of the chamber. The pins are lowered further after the board is installed and then separated from the board, ie there is no contact between the pins and the board. After the robot arm is moved and the chamber is closed (and the process gas is introduced or vacuum is applied), the process steps are performed.

In particular, the effect of relieving forces on the substrate after process steps have been performed in the chamber and during subsequent lifting of the substrate is extremely important. Generally, the substrate has a relatively smooth surface that contacts and rests on the carrier during the installation process. When attempting to remove the substrate from the carrier, the negative pressure acting between the substrate and the carrier may cause a kind of sticking caused, for example, by air pockets. If the substrate is pushed out of the carrier too abruptly, at least at the contact points, the contacting force cannot be overcome or relieved and the substrate can break. Furthermore, even if contact is established between the lifting pins and the substrate, impacts on the substrate may result in undesirable stress (or breakage). Therefore, the application of force to the substrate is an important consideration in handling the substrate within the chamber.

At the same time, the aim is to handle the substrates to be processed as gently and carefully as possible and to keep the processing time as short as possible. This means that the substrate can be brought into the defined states, ie loading position, unloading position and processing position, in the chamber as quickly as possible.

For example, to avoid unwanted shocks during processing of semiconductor wafers, US Pat. No. 6,481,723 B1 proposes the use of special stop means instead of hard motion stops in pin lifters. It replaces the hard plastic stop with a combination of a soft stop member and a hard stop that is damped on contact with the first soft stop member and then damped on contact between the soft stop member and the hard stop.

US Pat. No. 6,646,857 B2 proposes control of lifting movements by sensed generated forces. The lifting pins are movable in response to received force signals, so that the lifting force on the lifting pins acts on the wafer in a controlled manner at all times.

A further aspect of working processes involving vacuum conditions and voltage application is the potential influence of sources of electrical and/or magnetic interference. In such situations, the influence on the mechanical process should be taken into account, especially when designing the pin lifting system. For example, US Patent Application Publication No. 2005/0092438 A1 proposes a lifting device in which a non-conductive material can be used to electrically isolate the lifting pins from the control plate.

Of course, the component parts moved by the vacuum regulator are also exposed to the effects of the mechanical process as they reside within the process space. As a result, these parts may experience increased wear and tear and typically require periodic or on-demand maintenance or periodic or as-needed replacement.

In the case of vacuum regulators designed as pin lifting devices, the lifting pins are particularly subject to these wear and have to be replaced accordingly.

In the case of vacuum regulators designed as vacuum valves, the valve closure (valve disc) is particularly subject to process-related wear. As such, these closures are subject to such special maintenance requirements.

In general, vacuum valves for regulating volume or mass flow rates and/or for essentially hermetically closing a flow path conducted through an opening formed in a valve housing are conventional in various embodiments. It is known from the art and is used in the vacuum chamber systems mentioned above, especially in the IC, semiconductor or substrate manufacturing sector, which has to be carried out in a protected atmosphere as free as possible from contaminating particles. Both during mechanical processing in process vacuum chambers and during transfer from chamber to chamber, highly sensitive semiconductor devices or substrates must always be within a protective atmosphere, especially a vacuum environment. .

For this purpose, on the one hand, preference valves are used for opening and closing the gas supply or evacuation, and on the other hand, transfer valves for opening and closing the transfer openings of the vacuum chamber for inserting and removing parts. Used.

Vacuum valves through which semiconductor components pass are called vacuum transfer valves due to the described application and related areas, and also rectangular valves due to their predominantly rectangular opening cross-sectional shape, and slide valves due to their normal mode of operation. , also called rectangular slide valve or transfer slide valve.

A preference valve is used to control or regulate the flow of gas between a vacuum chamber and a vacuum pump or between other vacuum chambers. The preferential valves are arranged, for example, in the pipe system between the process vacuum chamber or transfer chamber and the vacuum pump, atmosphere or other process vacuum chamber. The opening cross section of such valves, also known as pump valves, is usually smaller than that of vacuum transfer valves. Depending on its area of application, preferential valves are used not only to fully open and close the opening, but also to adjust the flow rate by continuously adjusting the opening cross-section between the fully open and hermetic closed positions. They are also known as regulating valves because they are also used for control or regulation. A preferential valve for controlling or regulating gas flow may be a pendulum valve.

In a typical pendulum valve, as is known for example from the example of U.S. Pat. No. 6,089,537 (Olmsted), in the first stage, a normally circular valve disc opens into a normally circular opening. rotatably pivoted via the portion from a position releasing the opening to an intermediate position covering the opening. As described in U.S. Pat. No. 6,416,037 (Geiser) or U.S. Pat. No. 6,056,266 (Brecha), in the case of a slide valve, the valve disc, like the opening, is usually Rectangular in shape, in this first step it is pushed linearly from a position that releases the opening to an intermediate position that covers the opening. In this intermediate position, the valve disc of the pendulum or slide valve is in a spaced apart position facing the valve seat surrounding the opening. In a second step, the distance between the valve disc and the valve seat is reduced so that the valve disc and the valve seat are pressed evenly against each other and the opening is substantially hermetically sealed. This second movement is preferably in a direction substantially perpendicular to the valve seat. The seal is realized, for example, either by a sealing ring arranged on the closed side of the valve disc, pressed against the valve seat surrounding the opening, or by a sealing ring on the valve seat side, against which the closed side of the valve disc is pressed. can do. These two-step closing processes impart little shear force to the sealing ring between the valve disc and the valve seat to destroy the sealing ring. This is because the movement of the valve disc in this second step is essentially linear with respect to the valve seat.

Looking at the vacuum regulators mentioned above, in particular the pin lifting system and the vacuum valve, they have in common that they are each connected to a vacuum space, ie a process chamber. Within the process space a defined process atmosphere, in particular a certain internal pressure, is usually set for carrying out a defined mechanical process. Such a precisely regulated internal pressure, for example in relation to the process gas used, is part of the process programme, ie an important parameter with respect to guaranteeing the process quality to be ensured. In other words, it can be said that the reliability of the internal pressure setting has a corresponding influence on the reliability of the mechanical process.

Pressure sensors placed in or connected to the process space are commonly used to measure and monitor the process atmosphere. Providing one or more such pressure sensors at the same time implies additional costs in constructing the vacuum system, in particular with respect to tightness and avoidance of potential misalignments. Moreover, such sensors are also an additional source of error in the system, ie failure of one of these sensors may bring the process to a complete halt.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a solution that avoids the above-mentioned drawbacks.

In particular, it is an object of the present invention to provide an improved vacuum regulator that helps avoid the above-mentioned drawbacks.

The invention is also based on the object of providing respectively improved vacuum regulators for reliable process performance.

These objects are solved by realizing the features of the independent claims. Features which develop the invention further in alternative or advantageous ways can be taken from the dependent claims.

The present invention is realized on the basis of the structural design, in particular the precise knowledge of the dynamic behavior in the vacuum regulator, and with such knowledge the device can be further functionally extended, and that the mechanical process Allows access to further information about Thus, additional information about the vacuum process can be provided without requiring additional components to generate that information.

More specifically, within the scope of the present invention, the motor of the regulator is operated by control commands and is further processed by receiving current feedback based on the state of the motor, i.e. during operation, the actual state of the motor (e.g. total motor load) is recorded. In addition to this actual state, a corresponding target state (eg, motor system load) is known for the motor. This target state indicates, for example, under what conditions (eg, temperature, pressure, humidity, accumulated motor hours, total operating hours, etc.) and how much load should be imposed on the motor.

Additional information can be obtained from the comparison of actual and target conditions, which can indicate key operating conditions. In particular, the differential pressure can be derived from the difference in load or force thus measured.

The present invention relates to a vacuum regulation device for active devices movable in process atmospheres, especially vacuum regions. The vacuum regulator has a coupling designed to connect the active elements and a drive unit containing an electric motor which adjusts the coupling from a normal position to an active position and back by means of the electric motor. It cooperates with the coupling to enable it and is designed to do so.

In the normal position, the active element is essentially ineffective with respect to its intended effect in the coupled state (ie, the active element is connected to the coupling). In the active position, the active element in the coupled state exerts its intended effect (eg transports the substrate or closes the opening of the valve).

The vacuum regulator also includes a mechanical interface for connecting the vacuum regulator to a process space that provides a process atmosphere, and a dynamic dynamic interface that separates the process atmosphere from an external atmosphere area to define a process atmosphere area. an isolation device, wherein the drive unit is at least partly assigned to the external atmosphere region and the coupling is assigned to the process atmosphere region, and is at least electrically connected to the drive unit and controls the electric motor and a control processing unit designed to

In particular, the dynamic separating device is coupled or connected to the drive unit and/or the coupling such that when the coupling is adjusted, the separating device partially moves accordingly.

The control processing unit is adapted to derive motor status information based on the magnitude of the received motor operating parameter, wherein the magnitude of the motor operating parameter is at least the total motor power during controlled operation of the electric motor. Depends on load. The control processing unit also has a pressure measurement function, and when the pressure measurement function is performed, a load difference is derived by comparing the motor state information with a known motor target state, where , the known motor target state depends on at least the current state of the components of the vacuum regulator adjustable by the drive unit, and the differential pressure between the external atmosphere area and the process atmosphere area is derived based on said load difference. be done.

In one specific embodiment, the control processing unit is designed to derive the absolute pressure of the process atmosphere region based on this differential pressure. For this purpose, in particular information about the current pressure in the external atmosphere region can be used. This information can be obtained by measuring pressure or as a known quantity.

This provides a direct pressure measurement inside the vacuum process chamber. Each measurement may be provided as an output and can be used, for example, to control or regulate a mechanical process within the process chamber. In particular, pressure information (absolute or differential) can be considered for setting or adjusting process pressure.

In one embodiment, the motor operating parameter is motor current applied to the electric motor. This provides a measurement of the actual motor current, which is input to and processed by the control processing unit.

A motor operating parameter can be embodied as the ratio of the adjustment distance traveled by the coupling to the operating time required. In other words, the time required to move the coupling may be measured.

In one design, the control processing unit may be designed such that the motor status information is derived as the drag exerted on the electric motor from the ratio of the travel adjustment distance and the operating time required.

According to the invention, in one embodiment the motor target state may be the motor target current to be applied to the electric motor in the corresponding regulation state (operating state). For example, the motor current to be applied is known in advance as having a course over the adjustment distance movable by the electric motor or related to the motor rotation speed, in particular the operating time.

In one design, the known motor target state can be determined at least by the load acting on the drive unit or electric motor via the coupling and/or isolation device. This load is measured in part by, for example, the bellows resistance, i.e. the force required to compress the bellows over a defined travel distance, or by the loading force of the valve closure or pin (pin lifting device). be able to. This allows the motor target state to be changed within a certain adjustment distance. Such changes are also known and can be measured and stored.

According to one embodiment, a known motor target state can form a dynamic (varying) reference value over an adjustment distance defined by the adjustable width of the coupling.

In one design, the known motor target state is
- calibration of the adjustment displacement movement of the coupling within the range of adjustment distances provided by the adjustment device, in particular calibration with the speed function of the adjustment distance-movement time;
- models describing the vacuum regulator, in particular digital computer models,
- simulated adjustment conditions in the adjustment distance range defined by the adjustable width of said coupling; or - determined by average values of loads and/or forces measured during repeated cycles of reference motion.

In one embodiment, the drive unit can interact with the separating device such that the separating device is adjustable by an electric motor from a normal position to an active position and back. For example, the separating device may be directly connected to the drive unit or indirectly connected to the drive unit, for example via a coupling.

This dynamic separating device can be designed in particular as a bellows or seal, in particular as a diaphragm bellows or diaphragm seal. Thus, the isolation device provides a dynamic seal that remains effective even when moved within a certain distance.

The regulating device is specifically designed for use in the vacuum area, part of the regulating device operates within the vacuum area and another part, preferably part of the drive unit, is outside the vacuum area. . A separation device for atmospheric separation of these two regions may also be provided by the drive unit for this purpose and may be formed, for example, by the housing or bellows of the drive unit.

Alternatively, the separation device can be provided with a coupling that moves partially or completely out of the vacuum range. The separating device can for example be connected to the chamber wall of the process chamber.

The separating device can also be designed, for example, as a slide bushing sealed with an O-ring.

The drive unit can be designed for movement on the linear axis of the coupling, along and/or parallel to an adjustment axis.

According to embodiments of the invention, the active element can be realized as a lifting pin of a pin lifting device or as a valve closure of a vacuum valve.

According to one embodiment, the vacuum adjustment device is a pin lifting device, in particular a pin lifter for moving and positioning a substrate, in particular a wafer, to be processed in a process atmosphere region that can be provided by a vacuum process chamber. , in particular the coupling as a first coupling comprising a plurality of couplings.

Here, the drive unit provides at least linear adjustment of the first coupling. The active position is made as a mounting position where the pin lifting device is attached to the substrate, and the coupling is designed to accommodate the lifting pins designed to contact and support the substrate and form the active element. It is The intended effect of the active elements here (lifting pins) is transport, lifting and lowering of the substrate to be processed.

The normal position provided by the linear movement capability of the first coupling is represented in particular by the lowered position of the lifting pin, where there is no contact with the substrate.

In a further embodiment, the vacuum regulator can be designed as a vacuum valve, in particular a vacuum slide valve, a pendulum valve or a monovalve, for controlling the volume flow or mass flow and/or for hermetically blocking the flow path. . The vacuum regulator comprises a valve seat comprising a valve opening defining an opening axis and a first sealing surface surrounding said valve opening; (the intended effect) of a valve closure forming an active element, in particular a valve disc, the valve closure having a second sealing surface corresponding to said first sealing surface.

This valve closure is connected to a drive unit by a coupling, and from an open position as a normal position where the valve closure and the valve seat of the vacuum valve face each other in a non-contact manner, the first sealing surface and the second sealing surface are separated from each other. Sealing contact is made through an intervening seal whereby the valve opening is made adjustable to and from a closed position as an active position in which the valve opening is hermetically closed. The coupling is designed to accommodate the valve closure.

The device according to the invention is explained in detail below by way of specific embodiments schematically shown in the drawings by way of example only, in which further advantages of the invention are also discussed.

FIG. 1 shows a schematic diagram of one embodiment of a vacuum processing system for wafers with a vacuum regulator according to the invention. FIG. 2 shows an embodiment of the vacuum adjustment device according to the invention designed as a pin lifting device. FIG. 3 shows another embodiment of the vacuum adjustment device according to the invention, designed as a pin lifting device. FIG. 4 shows an embodiment of a vacuum regulator according to the invention designed as a vacuum valve.

FIG. 1 schematically shows a process setup for processing a semiconductor wafer 1 under vacuum conditions. A wafer 1 is transferred by a robot arm 2 into a vacuum chamber 4 (process atmosphere P) via a first vacuum transfer valve 5a of the vacuum regulator and is placed in the vacuum regulator designed according to the invention. is positioned by the lifting pins 7 of the pin lifting device (three pins are shown). The wafer 1 is then picked up or placed on the pins 7 and the robot arm 2 moves out. The pins of the pin lifting device are now in the extended carrying position. The wafer 1 is usually placed on a transport device provided on the robot arm or on the robot arms 2, 3, or is held by a special transport device. After the wafer 1 has been picked up by the pins 7, the robot arm is guided out of the chamber 4, the transfer valve 5a is closed and the pins 7 are lowered (to the normal position). This is done by a device 6 of the pin lifting device, connected to each pin 7 . In this way the wafer 1 rests on the four carrier elements 8 shown.

In this state, the desired process (eg coating) on the wafer 1 is carried out under vacuum conditions, in particular under a defined atmosphere (ie process gas at a defined pressure). For this purpose, the chamber 4 is connected to a vacuum pump and preferably has a vacuum regulating valve (not shown) for regulating the chamber pressure.

After the process has been performed, the wafer 1 is lifted again to the removal position (carrying position) by the pin lifting device. Then, the second robot arm 3 carries out the wafer 1 to the second transfer valve 5b. Alternatively, the process can be designed with only one robotic arm, in which case loading and unloading can be performed via a single transfer valve.

FIG. 2 shows one embodiment when the vacuum adjustment device according to the invention is a pin lifting device 10 .

Lifting pin 19 is locked to coupling 18 of device 10 . The lifting pin 19 preferably comprises a metallic, polymeric or ceramic material, and in particular the entire pin 19 is preferably made of such material. Locking of the coupling 18 can be achieved magnetically or by clamping, for example.

Coupling 18 is movable in the z-direction by means of slide 14 . For this purpose the slide 14 is connected to a threaded spindle 13 which is driven by the motor 12 of the drive unit.

Optional thermal and electrical insulation between the upper coupling part and the lower drive part can, as a variant, thermally and electrically separate the upper housing part from the lower housing part. realized by one insulating element 16 . Preferably, a second insulating element embodied by slide 14 may be provided. In this variant of the pin lifting device 10, a threaded pin is provided so that no contact (electrically and thermally conductive) occurs between the spindle 13 and the coupling 18 (even with relative movement). spindle 13 is precisely and rigidly designed and mounted. Alternatively, the spindle 13 is made of or coated with non-conductive or heat-insulating materials. This provides complete electrical and thermal isolation between the upper and lower parts in any state of the device 10 . In yet another variant, both the threaded spindle 13 and the slide 14 mounted on the spindle 13 can be electrically conductive (eg metal). Insulation can then be realized in particular by an intermediate sleeve, for example between the spindle/slide and the coupling.

While the electrical isolation described above is purely optional, it is understood that the invention extends to embodiments without such isolation.

The pin lifter 10 also has a bellows 15 inside. The bellows 15 is arranged to provide atmospheric isolation between the process atmosphere area P, where the pins 19 (pins) are present and mechanical processes usually take place, and the external atmosphere area A, where for example the drive 12 and other peripheral components are present. and formed. Bellows 15 is compressed upon extension of pin 19 while maintaining atmosphere isolation.

In the variant shown, the adjusting slide 14 moves both the coupling 18 and the bellows 15. FIG. Both the coupling 18 and the bellows 15 are at least indirectly connected to this slide. In particular, slide 14 is connected to coupling 18 , which is connected to bellows 15 . Also, the second end of the bellows is connected to the housing of the pin lifting device.

The connection of the individual components is made in a particularly airtight manner.

The pin lifting device 10 is connected to the housing 20 of the vacuum process chamber. This connection is designed so that the internal process atmosphere of the process chamber also influences the inside of the pin lifting device 10 . The feedthroughs in the housing wall 20 provided for the pins 19 ensure that the process atmosphere extends into the lifter 10, i.e. part of the process space and the internal space of the pin lifter 10 are common. A process atmosphere region P is formed.

A process atmosphere region P is defined within the pin lifting device 10 by at least the bellows 15 . The inner bellows space defined by the bellows 15 is part of the process atmosphere region P. Furthermore, axial movement, in particular, is restricted in the lower part of the coupling 18 . The atmosphere region separated from the process atmosphere region P is basically the outside atmosphere region A. As shown in FIG.

In the process atmosphere zone P, there is usually a much lower pressure than the pressure in the outer atmosphere zone A. Thus, also in the process atmosphere region P of the vacuum process chamber, there is a very low pressure, especially for mechanical processing of the workpiece. Vacuum conditions are usually dominant there. It can be assumed that there is a large pressure difference between the process atmosphere P and the external atmosphere A during operation of the pin lifting apparatus 10 .

The present invention utilizes this differential pressure.

In order to move the movable system components, in this case the coupling 18 and the bellows 15, the electric motor 12 has to overcome the system loads that occur on these components. This load depends on the structural design of the component (eg mass), movement characteristics (eg friction), and current conditions (eg position, bellows compression, etc.). This motor system load (motor target state) is known for the pin lifter 10 or may be measured by calibration and stored in the control system. For this purpose, a look-up table, a sufficiently accurate model describing the pin lifter 10, or a motor teaching process (repeating, monitoring, comparing, recording the motor motion sequence) can be used. Thus, the motor system load describes the respective target state of the electric motors during operation under defined conditions taking into account environmental conditions such as pressure, temperature, among others.

A control processing unit is provided for operating the lifter 10 (not shown). Appropriate signals (motor control signals) are supplied to the motor 12 for target control, eg movement to a given pin position. Motor operating parameters are provided in operating the motor 12 . The range of motor operating parameters during which the electric motor is in control depends on the total motor load, ie, represents the load currently being applied to motor 12 . For example, the motor operating parameter can be the motor current applied to the motor at any point in time.

The control processing unit is arranged to be able to derive motor status information from the motor operating parameters, ie to be able to quantify, for example, the current motor load or the current motor current. Thus, the control processing unit determines the actual state of the electric motor.

This actual state can then be related to a known motor target state, ie the motor state information can be compared to a known motor system load (motor target state). Based on an accurate knowledge of the motor system load, the load difference, ie the difference between the target load and the actual load, can be derived.

From the load difference obtained in this manner, the differential pressure between the external atmosphere region (A) and the process atmosphere region (P) is derived. By knowing the atmospheric pressure existing in the external atmospheric region (A), the process atmospheric region (P), ie the absolute pressure within the process chamber, can be determined.

Thus, according to the present invention, the vacuum regulator provides enhanced pressure measurement capabilities.

A (continuous) comparison of current motor operating parameters against a stored reference function (motor system load) also allows process monitoring and recording of process space conditions. For example, if the maximum allowable deviation is exceeded, a corresponding signal can be generated and output to indicate an unacceptable system condition and, if necessary, recommend a system check.

Long term monitoring of motor operating parameters can be used to determine both wear of one or more components of the pin lifting device and process quality. Thus, by observing the repetition of similar process steps (process cycles) over time, it is also possible to detect trends in changes in the process. Trend monitoring also enables prediction of future system conditions and corresponding development of optimized maintenance cycles.

FIG. 3 shows one embodiment of a pin lifting device 30 according to the invention. The pin lifting device 30 is shown in its lowered normal position.

FIG. 3 shows the drive unit of the pin footing device 30 with the motor 32 (electric motor). Motor 32 may be, for example, a servo motor or a stepper motor. The drive unit is connected to a shaft here designed as spindle 33 , ie shaft 33 is rotatable by motor 32 . This rotation can be controlled or adjusted in a controlled manner, for example depending on a given number of rotations. Controlled motion is possible eg with an encoder, where the encoder provides a control variable about eg the axial position of the bearing pin. In the illustrated example, the spindle 33 has an external thread. This thread can be designed as a trapezoidal thread, an acute angle thread or a round thread. By properly controlling the motor 32 in this manner, the threaded rod 33 (spindle) can be rotated.

The pin lifter 30 according to the invention also comprises a sliding guide element 31 . The slide guide element 31 has a central recess extending in the axial direction of the slide guide element 31, here coaxially with the adjustment axis V. As shown in FIG. A female thread is provided in this recess. The female thread can be, for example, cut directly into the slide guide element 31 , ie into the material of the slide guide element 31 . Alternatively, the recess can comprise, for example, a sleeve with internal threads.

The sliding guide element 31 is connected with its female thread to the male thread of the spindle 33, ie the male and female threads correspond and interact. The male thread meshes with the female thread. The spindle 33 is directly coupled only to the sliding guide element 31 as moving element. In other words, the spindle connects the drive 32 to the slide guide element 31, in particular to the slide guide element 31 only.

This interaction allows the sliding guide element 31 to move in the fore-and-aft direction along which the adjustment axis V extends by rotating the spindle 33 . This movement can thus be performed axially along the adjustment axis V. FIG. For this purpose, the slide guide element 31 can be mounted in such a way that it is substantially free of rotational movement about said adjustment axis and can only be moved axially.

The slide guide element 31 is also connected to the coupling 38 of the pin lifting device 30 . This allows the coupling 38 to move axially as well as the slide guide element 31, in particular from the illustrated lowered normal position to the extended carrying position.

Coupling 38 has a receptacle 37 for receiving a lifting pin. Such lifting pins are preferably designed to contact and support a substrate (eg a semiconductor wafer). The receptacle 37 comprises a ring or helical spring that clamps the lifting pin within the coupling 38 . However, the receptacle can also have other locking means (retaining rings, magnets, screws, etc.). A lifting pin can be inserted from above along the axis V for this purpose, in particular through an opening provided in the receptacle 37 of the coupling 38 .

The slide guide element 31 thus forms a connecting element as means for finally displacing the lifting pin by means of a drive.

By choosing a suitable material, the movement of the slide guide element 31 can be performed with low friction and without lubricant. For example, PTFE or other non-stick materials can be selected as manufacturing materials or surface coatings. The slide guide element 31 and/or its inner surface can comprise this material.

The pin lifter 30 also has a bellows 35 as an atmosphere separation device. The upper end of bellows 35 is connected to the housing of pin lifter 30 either indirectly (eg, by a head-mounted housing seal) or directly. The upper end of bellows 35 is connected to coupling 38 (the base of coupling 38). Each connection is formed in an airtight manner. The internal volume or axial extension of bellows 35 can be varied, particularly while maintaining atmospheric separation between the process atmosphere and the external atmosphere.

Bellows 35 and coupling 38 are connected such that coupling 38 provides bellows 35 with a one-sided atmospheric seal. Thus, the bellows 35 and the coupling 38 define the process atmosphere region P.

As a result of this arrangement, driving the spindle 33 allows linear movement of the coupling 38 with the bellows 35 within the pin lifting device 30 .

The pin lifting device 30 is connected or flanged to the process chamber 20 by a threaded connection. This causes the volume of the process chamber to be expanded by the internal volume of the pin lifter 30 defined by each side of the bellows 35 and coupling 38, which forms the process atmosphere region P. It is separated from the external atmosphere area A in an airtight manner.

The pin lifting device 30 has a control processing unit and algorithm corresponding to the embodiment shown in FIG. It is designed to measure between atmospheric regions A.

FIG. 4 shows another embodiment in which the vacuum regulator 40 according to the invention is a vacuum slide valve. The vacuum slide valve 40 has a valve housing with an opening 42 having an opening axis O and an elongated, generally rectangular valve seat 43 surrounding the opening 42 in the valve wall. The closure element 50 , in particular with its closing side on the process side, has a slightly larger cross-section than the opening 42 and closes the opening 42 substantially gas-tight by pressing the closing side against the valve seat 43 . The closure element 50 is supported by two valve rods 46 arranged parallel to each other. A closure element 50 is connected to the valve rod by a coupling. This connection can be achieved by screwing or clamping. A side view of the valving rods is shown in FIG. 4, so only one valving rod 46 is visible. According to another embodiment in accordance with the invention, only a single valving rod 46 may support closure element 50 .

This valve housing separates a vacuum area 51 in which the opening 42 , the valve seat 43 and the closing plate 50 are arranged, and an actuation area 52 outside the vacuum area 51 .

The two valve rods 46 are designed as diaphragm seals or diaphragm bellows 45 in the valve housing from the vacuum area 51 to the drive area 52 into two airtight feedthroughs with seals (e.g. O-rings) at the ends. is inserted. The diaphragm seal or diaphragm bellows 45 is designed to allow the valve rod 46 to move along the longitudinal and transverse axes within a range of motion while maintaining an airtight seal.

Since the drive region 52 is separated from the vacuum region 51 in an airtight manner, atmospheric pressure prevails within the drive region. Frictional particles in drive region 52 cannot enter the delicate vacuum region. A drive unit with a motor is arranged in the drive area 52 .

The drive unit moves the two valve rods 46 from an open position to an intermediate position along the longitudinal axis in the longitudinal closing direction z, and moves the two valve rods 46 in the transverse closing direction, extending perpendicular to the longitudinal axis. It is designed to move the closure plate 50 from the open position to the intermediate position shown by reciprocating adjustment from an intermediate position along the transverse axis in y to the closed position (L because the closure plate is L-shaped). type).

A vacuum slide valve 40 or its opening 42 is designed to connect to a vacuum process chamber. The process atmosphere within this chamber extends up to and including the vacuum region 51 of the vacuum slide valve 40 . In other words, a process atmosphere region P including at least both the space of the vacuum chamber and the vacuum region 51 of the vacuum slide valve 40 is formed. This process atmosphere zone P is separated from the external atmosphere zone A by a sealed bellows 45 . The drive region 52 is part of the ambient atmosphere region A. FIG.

The vacuum slide valve 40 has a control processing unit designed and constructed to measure the differential pressure between the process atmosphere P and the external atmosphere A. For this purpose, a known target system load (target valve state) is compared during operation with currently provided operating parameters (eg applied motor current). The differential pressure can be estimated from the load difference derived thereby.

Since the pressure in the process atmosphere area P is lower than the pressure in the outside atmosphere area A, for example, the greater the differential pressure, the smaller the current operating load during the closing operation.

Therefore, it is possible to derive the differential pressure on the basis of the load differential, in particular by pre-calibrating the system, i.e. by determining a function describing the relationship between the motor load differential and the ambient pressure differential. can.

Finally, this idea can also be used to measure the absolute process pressure (if the existing pressure in the external atmospheric region A is known) and thus also for process monitoring in vacuum mechanical processes. can be used.

It is understood that the shown figures only schematically illustrate possible embodiments. According to the invention, different approaches can be combined with each other as well as vacuum equipment especially for substrate processing (eg pin lifters) or prior art vacuum valves.

Claims (14)

A vacuum adjustment device (5a, 5b, 6, 10, 30, 40) for active elements (7, 19, 50) movable in a process atmosphere region (P), in particular a vacuum region, comprising:
couplings (18, 38) designed to connect said active elements (7, 19, 50);
A drive unit comprising an electric motor (12, 32), said electric motor:
from a normal position in which said active element (7, 19, 50) is essentially ineffective with respect to its intended effect,
to an adjustable active position in which said active element (7, 19, 50) in coupling exerts its intended effect;
a drive unit interacting with the coupling (18, 38) and designed such that the coupling (18, 38) is adjustable;
a mechanical interface for connecting said vacuum regulator (5a, 5b, 6, 10, 30, 40) to a process space providing a process atmosphere;
A dynamic isolation device (15, 35, 45) for isolating a process atmosphere from an ambient atmosphere area (A) to define said process atmosphere area (P), wherein said drive unit is connected to said ambient atmosphere area. a dynamic isolation device (15, 35, 45) at least partially assigned to (A) and said coupling (18, 38) assigned to said process atmosphere region (P);
a control processing unit at least electrically connected to said drive unit and designed to control said electric motor (12, 32);
has
The control processing unit
designed to derive motor status information based on the magnitude of a motor operating parameter dependent at least on the total motor load during controlled operation of said electric motor (12, 32), and comprising a pressure measurement function; has
Here, the pressure measurement function unit
load by comparison with motor state information against a known motor target state, dependent on at least the current state of the components of the vacuum regulator (5a, 5b, 6, 10, 30, 40) adjustable by the drive unit; Derive the difference,
Designed to derive the differential pressure between the external atmospheric area (A) and the process atmospheric area (P) from the load difference,
A vacuum regulator (5a, 5b, 6, 10, 30, 40), characterized in that: Vacuum regulator (5a, 5b, 6, 10, 30, 40) according to claim 1, characterized in that said motor operating parameter is the motor current applied to said electric motor (12, 32). . Vacuum regulator according to claim 1 or 2, characterized in that the motor operating parameter is embodied as the ratio of the adjustment distance traveled by the coupling (18, 38) and the operating time required for it. 5a, 5b, 6, 10, 30, 40). 4. The method according to claim 3, characterized in that the control processing unit is designed such that the motor state information is derived as a drag force exerted on the electric motor from the ratio of the movement adjustment distance and the required operating time. Vacuum regulator (5a, 5b, 6, 10, 30, 40) as described. Vacuum according to any one of the preceding claims, characterized in that the known motor target state is the motor target current to be applied to the electric motor (12, 32) in the corresponding regulation state. adjustment device (5a, 5b, 6, 10, 30, 40); CHARACTERIZED IN THAT said known motor target state is defined at least by the load acting on said coupling (18, 38) and/or said separating device (15, 35, 45) of said drive unit or on an electric motor. A vacuum regulator (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 5. Any one of claims 1 to 6, characterized in that said known motor target state forms a dynamic reference value over an adjustment distance defined by an adjustable width of said coupling (18, 38). 5. A vacuum regulator (5a, 5b, 6, 10, 30, 40) according to the preceding paragraph. The known motor target state is
adjustment movement of said coupling, in particular calibration as a function of movement/movement time;
a model describing the vacuum regulator;
simulation of the adjustment conditions over the adjustment distance defined by the adjustable width of said coupling (18, 38); A vacuum regulator (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 7, characterized in that The drive unit adjusts the separation device (15, 35, 45) such that the separation device (15, 35, 45) is adjustable by the electric motor from the normal position to the active position and back. Vacuum regulator (5a, 5b, 6, 10, 30, 40) according to any one of the preceding claims, characterized in that it interacts with a 10. Any one of claims 1 to 9, characterized in that the dynamic separating device (15, 35, 45) is designed as a bellows (15, 35, 45) or a seal, in particular a diaphragm bellows or a diaphragm seal. A vacuum regulator (5a, 5b, 6, 10, 30, 40) according to claim 1. Claims 1-, characterized in that the drive unit is designed for movement on a linear axis of the coupling (18, 38), along and/or parallel to an adjustment axis (V). 11. Vacuum regulator (5a, 5b, 6, 10, 30, 40) according to any one of claims 10. Vacuum regulation according to any one of the preceding claims, characterized in that the active element (7, 19, 50) is designed as a support pin (7, 19) or a valve closure (50). Devices (5a, 5b, 6, 10, 30, 40). A vacuum regulator (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 12,
A process in which said vacuum adjustment device (5a, 5b, 6, 10, 30, 40) has made at least a process atmosphere zone (P) that can be provided by a pin lifting device (6, 10, 30), in particular a vacuum process chamber. a pin lifter for moving and positioning a substrate (1), in particular a wafer, to be
said pin lifting device having said coupling (18, 38) as a first coupling, in particular comprising a plurality of couplings,
here,
said drive unit providing linear adjustment of said first coupling (18, 38);
said active position being a mounting position for mounting said pin lifting device (6, 10, 30) to said substrate (1);
said couplings (18, 38) are designed to accommodate lifting pins (7, 19) designed to contact and support the substrate (1) and form active elements; A vacuum regulator (5a, 5b, 6, 10, 30, 40), characterized in that A vacuum regulator (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 12,
The vacuum regulator (5a, 5b, 6, 10, 30, 40) comprises a vacuum valve (40), in particular a vacuum slide, for controlling the volumetric or mass flow rate and/or for hermetically blocking the flow path. Designed as valves, pendulum valves or monovalves,
a valve seat (43) comprising a valve opening (42) defining an opening axis (O) and a first sealing surface surrounding said valve opening (42);
A valve closure (50) forming said active element (7, 19, 50), in particular a valve disc, for controlling a volume or mass flow rate and/or blocking a flow path, said a valve closure (50) having a second sealing surface corresponding to the one sealing surface;
wherein said valve closure (50)
From the open position as a normal position in which the valve closure (50) and the valve seat (43) of the vacuum valve (40) face each other in a non-contact manner,
such that said first sealing surface and said second sealing surface are in sealing contact through an intervening seal whereby said valve opening (42) is hermetically closed to a closed position as an active position and back. A vacuum regulator ( 5a, 5b, 6, 10, 30, 40).

Images